1. Field of the Invention
An embodiment of the present invention relates to a pneumoperitoneum apparatus, in particular, to a pneumoperitoneum apparatus that measures pressure in a body cavity in real time through a dedicated tube for pressure measurement that is coupled with the cavity.
2. Description of the Related Art
In recent years, to suppress invasion into a patient, a laparoscopic surgical operation is performed in which therapeutic treatment is performed without an abdominal operation. In the laparoscopic surgical operation, for example, a first trocar that guides an observation endoscope into a body cavity, and a second trocar that guides treatment instruments to a treated site are pierced into an abdomen of the patient. In the laparoscopic surgical operation, treatment, etc. is performed while the treated site and the treatment instruments that are inserted into the body cavity through an insertion hole of the second trocar are observed with use of the endoscope that is inserted into the body cavity through an insertion hole of the first trocar.
In such a laparoscopic surgical operation, a pneumoperitoneum apparatus is used in order to secure a visual field of the endoscope and to secure a region in which the treatment instruments are operated. The pneumoperitoneum apparatus injects, for example, carbon dioxide as pneumoperitoneum gas into the body cavity to expand the cavity at a predetermined pressure, thereby securing the visual field of the endoscope and the operation region of the treatment instruments.
Typically, the pneumoperitoneum apparatus uses a gas feeding tube that feeds gas into the cavity, to measure pressure in the cavity. Therefore, the pneumoperitoneum apparatus temporarily stops the gas feeding and then measures the pressure in the cavity, after feeding the gas into the cavity for a predetermined time period. Further, the pneumoperitoneum apparatus performs such intermittent gas feeding until the pressure in the cavity reaches a set pressure (for example, refer to Japanese Patent Application Laid-Open Publication No. 8-126606).
An apparatus disclosed in U.S. Pat. No. 6,299,592 detects crushing of an RTPS tube with use of the fact that, in a case where a small amount of gas is fed to the RTPS tube, excess pressure is applied to an inside of the tube when the tube is crushed.